The present invention relates to a printing cylinder/roller cleaning apparatus in various types of printing presses, which cleans the circumferential surface of a printing cylinder, e.g., a blanket cylinder, an impression cylinder, or a transfer cylinder, and the circumferential surface of a roller, e.g., a form roller or a vibrating roller, and a method of cleaning the printing cylinder/roller.
Each of various types of printing presses, e.g., an offset printing press and an intaglio printing press, has printing cylinders, e.g., a plate cylinder, a blanket cylinder, an impression cylinder, and a transfer cylinder, and rollers, e.g., a form roller and a vibrating roller. During the printing operation, foreign matters, e.g., ink dust and paper dust are attached to the circumferential surfaces of these printing cylinders and rollers to degrade the quality of the printed matter. Hence, a cleaning apparatus is provided for cleaning the printing cylinders and rollers to remove the foreign matters.
As an example of a printing cylinder/roller cleaning apparatus of this type, for example, an apparatus for cleaning the blanket cylinder disclosed in Japanese Patent Laid-Open No. 59-178254 is known. This apparatus has rewinding and take-up shafts. The rewinding and take-up shafts are close to the circumferential surface of the blanket cylinder and extend in the axial direction thereof. The two end portions of each of the rewinding and take-up shafts are rotatably axially supported by the bearings of the apparatus frame. One or two guide rollers are provided at the intermediate portion of each of these shafts. When the take-up shaft is driven by a driving unit to be intermittently rotated by a predetermined angle, a cleaning cloth, e.g., an unwoven fabric which is taken up on the rewinding shaft in a separate process is intermittently rewound from the rewinding shaft, is pressed by the guide roller against the circumferential surface of the blanket cylinder, and is taken up on the take-up shaft. A brush roller is provided above the traveling path of the cleaning cloth extending from the guide roller toward the take-up shaft to contact the circumferential surface of the blanket cylinder. The brush roller and the blanket cylinder are rotated in the same direction so that their peripheral rotational directions at the contact portions are opposite to each other. A nozzle for spraying a cleaning liquid toward the brush roller is provided above the brush roll. A reception pan (collecting tub) for collecting a waste liquid and the like is provided below the brush roll.
However, in the conventional cleaning apparatus described above, since the foreign matters and the waste cleaning liquid removed from the blanket cylinder are discharged to the reception pan, treatment of the waste liquid and the like accumulated in the reception pan and cleaning of the reception pan must be frequently performed. This increases the load of the operator and prolongs the preparation time, thus degrading the operability of the printing press. In the printing cylinder/roller cleaning apparatus disclosed in Japanese Patent Laid-Open No. 3-224739, in addition to the reception pan described above, a recovery unit is provided to be connected to the reception pan for removing the accumulated waste liquid and the like through a hose. However, with this arrangement, since the apparatus is complicated and its size is increased, the apparatus cannot be provided at a low cost.
Since the cleaning liquid from the spray hole of the nozzle is sprayed to one portion locally, cleaning non-uniformity is caused to be transferred from the brush roller to the blanket cylinder again, so that a sufficient cleaning result cannot be obtained. In order to solve this problem, an apparatus using a special nozzle is proposed. In this apparatus, a plurality of branch pipes are formed to extend from the nozzle, and the cleaning liquid is sprayed from holes formed in the branch pipes. Alternatively, another apparatus is proposed. In this apparatus, predetermined amounts of solvent and air are supplied to the piping path of the nozzle, so that the solvent is sprayed like a mist from the spray hole. However, in the former apparatus using such a special nozzle, since a large number of branch pipes are provided, the manufacturing cost is increased, the number of assembling steps is increased, and it is difficult to seal the branch pipes to prevent liquid leakage. In the latter apparatus for spraying the solvent like a mist, since air pipes must be provided in addition to solvent pipes, the manufacturing cost including the control system for the air and solvent pipes is increased, and wiring and piping operations become cumbersome. In addition, since the solvent is sprayed like a mist, it is scattered around to worsen the working atmosphere.
Furthermore, since the cleaning cloth pressed by the guide roller and the brush roller are pressed against the circumferential surface of the blanket cylinder simultaneously, when the cleaning cloth contacts the blanket cylinder for the first time, the cleaning cloth adhesively attaches to the circumferential surface of the blanket cylinder by the accumulated ink tack, thus damaging the cleaning cloth.